Brandorr wrote: > Is ZFS efficient at handling huge populations of tiny-to-small files - > for example, 20 million TIFF images in a collection, each between 5 > and 500k in size? > > I am asking because I could have sworn that I read somewhere that it > isn't, but I can't find the reference. > If you're worried about the I/O throughput, you should avoid RAIDZ1/2 configurations. random read performance will be desastrous if you do; I've seen random reads ratios with less than 1 MB/s on a X4500 with 40 dedicated disks for data storage. If you don't have to worry about disk space, use mirrors; I got my best results during my extensive X4500 benchmarking sessions, when I mirrored single slices instead of complete disks (resulting in 40 2-way-mirrors on 40 physical discs, mirroring c0t0d0s0->c0t1d0s1 and c0t1d0s0->c0t0d0s1, and so on). If you're worried about disk space, you should consider striping several instances of RAIDZ1 arrays, each one consisting of three discs or slices. sequential access will go down the cliff, but random reads will be boosted.
You should also adjust the recordsize. Try to measure the average I/O transaction size. There's a good chance that your I/O performance will be best if you set your recordsize to a smaller value. For instance, if your average file size is 12 KB, try using 8K or even 4K recordsize, stay away from 16K or higher. -- Ralf Ramge Senior Solaris Administrator, SCNA, SCSA Tel. +49-721-91374-3963 [EMAIL PROTECTED] - http://web.de/ 1&1 Internet AG Brauerstraße 48 76135 Karlsruhe Amtsgericht Montabaur HRB 6484 Vorstand: Henning Ahlert, Ralph Dommermuth, Matthias Ehrlich, Andreas Gauger, Matthias Greve, Robert Hoffmann, Norbert Lang, Achim Weiss Aufsichtsratsvorsitzender: Michael Scheeren _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
